Go to the Items settings, create an Item and make it a Group type Item, presumable with a type and aggregation function as well. Refrain from giving it any semantic tags.
The model is a way to view and organize some of your Items. It is not intended to be comprehensive. You can’t do everything Item related from there.
A little of both. Anything that uses the model is going to assume that a Point Item will only be a direct member of one semantically tagged Group. Period. That means, in the Model view the assumption is that any Item can only appear once in the tree. Therefore it’s a UI problem because it won’t show any Items in the model more than once. But it’s also a structural problem because anything that currently uses the model or will use the model in the future also has the same assumption. Since a sensor can’t be in two physical places at once, it can’t be a part of two Equipment or two Locations at once either. It can only show up in the model in one place.
But, this limitation does not apply to stuff that is outside the model. Your Item can appear in as many other Groups as you need. For example,
This is a smart outlet that controls a lamp. Notice it is semantically tagged as a Switch/Light Point Item and it is a member of the FrontroomLamp_Equipment Equipment which is tagged with the Equipment Lightbulb tag.
But you will also see it’s a member of seven other Groups. But none of those Groups are semantically tagged.
In the model view everything shows up as expected. It only appears once in the actual Model (since that is all that is allowed):
If I try top add the Item to another Group that has an Equipment or Location tag though the Switch will only appear in one of them because the assumption is that a Point can’t physically be a part of more than one Equipment or Location at the same time.
But, that restriction doesn’t apply to stuff outside the model. And indeed, if I check the box to show the stuff outside the model, my Switch appears everywhere it should.
But, the Model view really isn’t designed or intended to see, manage, and create anything outside the model. So setting up all that would be handled from the Item’s settings instead, not from the Model. IMO, the only reason to check the “show non-semantic” in the model view is if you have some Item you want to add to the model. Everything else is better handled through the Items Settings pages.